Blind rivets or rivets that can be installed by access to only one side of a workpiece are well-known in the art. Generally a blind rivet includes a tubular shell or sleeve that has a longitudinal bore. Also, included is a mandrel that generally has a head having a diameter greater than that of the bore of the shell or sleeve and including a shank extending from the head of the mandrel that is housed within the bore of the sleeve.
In use, the shank is inserted through aligned apertures formed in a workpiece that includes two parts to be riveted together. The shell is inserted through the aligned apertures in a workpiece such that the shell abuts a face of the workpiece. The mandrel is then inserted into the shell such that the shank of the mandrel protrudes beyond an opposite face of the workpiece. A pulling force is then applied to the mandrel shank relative to the shell. The pulling force causes the mandrel head to deform the shell radially outwards to form a blind head which abuts a face of the workpiece. In this manner, the workpiece members are clamped together between a preformed head of the shell and the blind head formed by the pulling force on the mandrel shank.
While blind riveting provides a useful method of attaching various structural components from one side, there is a need to improve the mechanical strength of such a riveted joint. Studies have shown that blind riveted joints provide higher fatigue strength as compared to other fastening methods such as spot welding, but they have less static strength. There is, therefore, a need to provide a blind rivet having improved static strength as well as providing a strong rivet bonded joint between the rivet and the material to be joined.